The invention(s) presented herein relate to tie downs for attachment of objects to vehicle frames. More particularly, this disclosure is directed to improved tie downs to secure camper bodies to pick-up trucks.
Tie-downs for mounting objects on motor vehicle frames are well known. Such tie downs are often provided for fixed installation to the frame, or to the underside of a vehicle (such as a pick-up truck), for securing a load (such as a camper) to the vehicle frame. Generally, four such tie downs are installed on a vehicle for securing the camper to the pick-up truck""s bed at or near all four corners. The tie downs used by others, in so far as they are known to me generally include a cantilevered telescoping arm projecting horizontally from a secure position on the vehicle frame. Such prior art tie downs include a rigid support member projecting perpendicularly from an outer sleeve of a cantilevered telescoping arm to fixedly attach to a point on the underside of the vehicle to brace the tie down when the load is secured. Also, such tie downs include a chain having one end attached to the end of the telescoping arm opposite the frame mount and the other end free for fixedly attaching to the load, such as a camper, to secure it to the vehicle. The load is secured to the vehicle by tensioning the chain using, for example, a turnbuckle. Thus tensioned, the chain is a rigid member unable to relieve sudden loads, such as those caused by shifting of the camper relative to the truck bed. Such sudden load, when not relieved, may exceed the stress-bearing capabilities of the joints mounting the tie downs to the vehicle and may loosen the joints and/or damage either or both of the vehicle and the tie downs. While a spring-loaded turnbuckle is known, it is a separate assembly from the tie down and forms no part of the tie down.
It is a drawback that the tie downs used by others must be professionally installed by qualified mechanics, primarily since they are normally provided from the factory in a single embodiment or configuration which requires drilling of additional mounting holes in the vehicle frame. The drilling of such holes in or adjacent to highly loaded or specially hardened steel frame members requires equipment and a skill level ordinarily available only to the professional installer. Furthermore, the warranties provided by many vehicle manufacturers might be violated or voided by the addition of such holes in the vehicle frame members. Therefore, such considerations severely limit the practical application of the known tie downs. Moreover, such restrictions have effectively prevented mail order or Internet distribution of such tie-down designs.
Undesirably, many tie downs also interfere with use of the vehicle even when the load is removed from the vehicle. This is because rigid support members, not easily or quickly removable, if at all, project from the sleeve of cantilevered telescoping arms, and thus places the tie down components in a position beneath the vehicle in a manner that may interfere with steps, bars and other platforms attached to many vehicles for ease of entry and exit. Many tie downs also interfere with use of the vehicle off-road, because they are positioned below the vehicle, near the ground, and might encounter brush, stumps, rocks and other low lying obstacles.
The present invention overcomes many limitations of prior art tie-downs by providing a tie down for mounting to hitches, frames, or other pre-existing mounting structure on a vehicle. The present invention thus overcomes the need (found in many prior art devices) to drill, cut, weld or otherwise provide custom mounting structure for a tie downs, and thus tie downs can be provided for each major brand of vehicle, without the need to customize every tie down installation.
According to one aspect of the invention, the present invention provides first and second spaced apart, mutually perpendicular frame brackets, each frame bracket adapted for mating with pre-existing mounting holes or other structure on a vehicle frame. Generally, the first frame bracket is mounted to a vertical portion of the frame while the second frame bracket is mounted to a horizontal portion of the vehicle frame, i.e., the bottom of the vehicle. The retractable nature of the tie down is provided by a telescoping arm pivotally mounted to a first frame bracket, whereby the telescoping arm is able to rotate relative to the first frame bracket. The telescoping arm includes an outer sleeve, one end of which is rotatably suspended by a pivot mechanism from a face of the first mounting bracket, an inner arm nested in the outer sleeve and able to move axially relative to the outer sleeve, and a releasable clamp which secures the inner arm in fixed axial relationship with the outer sleeve.
According to another aspect of the invention, a support strut extending between the telescoping arm and the second frame bracket secures the telescoping arm in a fixed orientation with each of the first and second frame brackets.
According to another aspect of the invention, the telescoping arm includes a movable slide having a clamp for securing the slide in variable positions along the body of the telescoping arm""s outer sleeve. The movable slide includes a second pivot mechanism projecting, to which one end of the support strut extending between the telescoping arm and the second frame bracket is pivotally mounted. The second or horizontally mounted frame bracket includes yet another pivot mechanism to which the other end of the support strut is mounted. Thus, one end of the support strut rotates about the pivot mechanism on the second frame bracket and the other end rotates about the pivot mechanism on the movable slide, while the slide moves along the longitudinal axis of the telescoping arm in order to allow the telescoping arm to rotate up and down relative to the first frame bracket, and thus into different angular orientations with respect to the vehicle frame.
According to still another aspect of the invention, the support strut is configured as a second telescoping arm and includes its own mechanism for locking its inner arm relative to its outer sleeve.
In yet still another aspect of the invention, the support strut is configured in a partially collapsed bent tubular configuration, so that a tubular insert is provided that is able to slide inside of a welded steel tube, without the need to remove weldment where the larger tube has been fabricated.
In yet still another aspect of the invention, a clamp is provided for attaching arms to a trailer hitch, which clamp eliminates the need to drill holes in a hitch or in a vehicle frame, in order to securely attach the arm to the hitch or frame.
In yet still another aspect of the invention, a bullet shaped (in cross-section) plate is provided to extend, either forward or aft, as the case may be, the attach point at the end of attachment arms, so that increased leverage is available to secure the load against shifting.
In yet another aspect of the invention, an easily adjustable clamp is provided for adjustment of arm positions relative to frame mounts.
In a still further aspect of the invention, a fixed size arm is provided with certain frame mounts, as such mounts easily serve a multitude of vehicles of the same make and/or model.
Various embodiments of the invention are disclosed in which the mechanical features described above are achieved in disparate physical configurations.